All of a s_________, the bedroom window flew open.
The firefighters tried to prevent the fire from _________ (蔓延)。
We're keeping you here for your own _________ (safe).
Sarah was very sad because she f_________ the math exam yesterday.
Mrs. Hu is very _________ (耐心的) with the children.
The food is too cold. Why not h_________ it before eating?
